object is passed through the encoder function found for the given
encoding using the error handling method defined by errors. errors may
be NULL to use the default method defined for the codec. Raises a
LookupError if no encoder can be found.

object is passed through the decoder function found for the given
encoding using the error handling method defined by errors. errors may
be NULL to use the default method defined for the codec. Raises a
LookupError if no encoder can be found.

In the following functions, the encoding string is looked up converted to all
lower-case characters, which makes encodings looked up through this mechanism
effectively case-insensitive. If no codec is found, a KeyError is set
and NULL returned.

Register the error handling callback function error under the given name.
This callback function will be called by a codec when it encounters
unencodable characters/undecodable bytes and name is specified as the error
parameter in the call to the encode/decode function.

The callback gets a single argument, an instance of
UnicodeEncodeError, UnicodeDecodeError or
UnicodeTranslateError that holds information about the problematic
sequence of characters or bytes and their offset in the original string (see
Unicode Exception Objects for functions to extract this information). The
callback must either raise the given exception, or return a two-item tuple
containing the replacement for the problematic sequence, and an integer
giving the offset in the original string at which encoding/decoding should be
resumed.